Water cone

(Figure) The scheme for the forming of the water coneWATER CONE (EN: water cone, aquatic cone, aqueous cone; DE: Wasserkegel; FR: cone d'eau; ES: cono de agua; RU: водяной конус) is the local uplift of the surface of the plantar water during the operating of the borehole within the petroleum or gas reservoirs. The forming of the water cone is determined by the character of the distribution of the hydrodynamic pressure within the surroundings of the bottomhole of the borehole, in case of which the vertical component of the gradient of the pressure and of the speed of the filtration has the maximal value at the lower end of the interval of the unsealing, which is situated above the petroleum-water contact, or above the gas-water contact (see the Figure). There exert the significant influence onto the forming of the water cone the anisotropy of the layer, and the depression of the layer pressure near the bottomhole of the borehole. For the stability of the water cone, there is necessary the compliance with the following condition:

at the point A (where R is the pressure; Z is the vertical coordinate; gv is the density of the water), in case of the violation of which, the apex of the water cone is sharpened, and the water breaks into the borehole. In case of the existence of the impermeable clayish interlayers with the significant area within the layer, the water flooding of the borehole is decreased using the plugging of the bottomhole up to the level of these interlayers. For the process of the cone forming, there is characteristic the non-stationarity, which is determined by the displacement of the petroleum (gas) by the water.